This invention relates to computer based teaching tools such as electronic calculators, and more particularly to a calculator or other computer teaching tool having shading of mathematical inequalities.
Electronic calculators have become a common tool for teaching students mathematics. In particular, the advantages of graphing calculators are being utilized in the classroom. Graphing calculators are characterized by a larger screen, which permits the entry of mathematical expressions in a logical format. They also permit graph displays and table displays. They have sophisticated programming capability. They often permit data transmission to other computing devices, directly or via a data storage medium, as well as data collection via various interface protocols.
Particular calculator models are often designed for particular educational levels. For example, a calculator for middle school students might have less advanced features than one designed for older students. However, regardless of the level for which a calculator is designed, a continual goal in designing them is to provide a logical and easy-to-use interface. Another area of concern is the ability to display a result on a small and comparatively low-resolution display screen.
The present invention is a computer based teaching tool or device for mathematical calculations such as a graphing calculator that displays inequalities on a display screen. In contrast to prior art devices, the present invention provides displays of inequalities that are mathematically correct and consistent with non-electronic display of inequalities such as textbooks and black board representations. This improved consistency and clarity in the display of the inequality helps to reinforce traditional teaching methods and helps the student or user to readily see and understand the mathematical concepts involved. The display methods of the present invention are particularly useful for small, low-resolution displays that are typical of handheld computers and calculators.
The calculator may otherwise be a conventional graphing calculator. Namely, the calculator screen is capable of two-dimensional displays and of displaying at least straight lines in any direction and a cursor. A key panel has keys at least capable of selecting positions of the cursor and moving the cursor horizontally or vertically on said screen. A processor is operable to execute graphing programming that instructs the processor to perform the following steps: display one or more xe2x80x9cX=xe2x80x9d prompts and xe2x80x9cY=xe2x80x9d prompts, allow user input of an inequality for one or more prompt, display each selected inequality on the display, allow the user to select union or intersection shading of the selected inequalities.
In an embodiment of the invention a calculator or other computer based teaching tool represents a graphed inequality with a dotted line to more clearly indicate the underlying mathematical principle of the graphed line to the user.
In a further embodiment of the invention, the intersection of the graphed inequalities is shown with a different shade style so the user can clearly see the union of the inequalities.
In another embodiment, the union of the defined inequalities is graphed on the display.